TPS Woes

Still having trouble with the F150. Even though I found and removed plastic from inside the distributor, problems continue.

I finally discovered a simple jump in the OBD connection wires will display trouble codes, so I ran them and it appears I've had a code come up (key off) for EGR (which I was berkeleying with so I can toss that one out), along with both TPS voltage too high and TPS voltage too low. After starting the truck, I received the code for limp mode and TPS voltage too low.

I grabbed the multimeter, sewing kit, and a flashlight to check the TPS. The ground is reading perfect, the input is strong at 4.9 V, but I'm reading 0 V at the return. I can understand the voltage not reacting to the throttle body screw, but 0 v kind of throws me off. I'm assuming grab a new sensor and test it wired up before installing?

Has anyone experienced this?

Vehicle in question is a 1995 F150 with a 302.

Can you pull the sensor and manually manipulate it to check for any readings?

In reply to Bruce:

That may be the next step. It is simply held on by two bolts. A bit of a pain in the ass to get to, but it may be the next step.

Didn't you get the memo about the TPS reports?

Once removed you should be able to turn the sensor input with a flat blade screw driver.

In reply to The_Jed:

I'll probably do that because I'm cheap and that's why I'm here.

In reply to T.J.:

I was really worried an Office Space joke wouldn't make it in before page two. Thanks for saving the day. I'm kind of upset it wasn't a meme, though.

Ok I'm done.

How's that TPS looking?

Bruce wrote: Can you pull the sensor and manually manipulate it to check for any readings?

Is there room to unhook the connector and check resistance readings across the sensor as you move the throttle? You should see a slight change, even if the sensor is bad...usually what you'll find with a bad sensor is rather than a gradual sweep it functions more like an on/off switch. If you don't measure any resistance change, then you either have problems with the mechanical connection, or that sensor is completely berkeleyed.

In reply to N Sperlo:

I was worried that a mention of Office Space would derail the thread and result in you not getting the answers you needed, so I didn't go with a meme, just the words.

If you are making good contact with your multimeter, you should have 5v, 0v, and sweep from around .5 to 4.5v on the return. With your numbers, either the sensor is open, you are not getting good contact with the meter, or the return wire is grounded somewhere.

I once dumped a saturn due to seven bad tps sensors in a year. And each time the dealer had to do something with the ecm to learn the sensor.

That was many years ago, and I'm pretty sure that if I knew then what I know now, things would have ended differently.

the other option is to just slap a new TPS sensor on and see what happens... I don't normally recommend the parts cannon but I think they are like $20.

IIRC 'learning' the new TPS on these fords is when you turn the key on, the ECU takes a resistance reading of the sensor, (usually about 1 volt) and marks it as 'throttle closed'. So basically any time you turn the key from off to on, the ECU has just 'learned' the TPS. I guess don't step on the gas when you turn the ignition key on. Anything over 3.7 volts or so is considered full throttle by the ECU.

I'll be removing the TPS, reading it while manipulating it and doing the same with a new one. If the new one reacts properly, I know the problem. If not, I'll keep looking.

Just an update. 0Ω and no continuity across input and return. Bought a new one and the readings were quite different. I'll install tomorrow along with the city mandated cleaning of my driveway.

You get those too? I get mine cause the ex calls the city for me. I just tell her hey I was gonna do that this weekend but now you gave me another two weeks.